async function fetchCount(id) {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      resolve(id);
    }, 1000);
  });
}

let count = 0;

async function addCount(id) {
  count += await fetchCount(id);
}
(async () => {
  await addCount(1);
  await addCount(2);
  await addCount(21);
  console.log(count);
})();
